Canon 100 mm f/2.8 USM Macro Question?

[phizz6]

Is there any reason you couldn't use this lens as a regular 100 mm lens to focus on distant objects or is it limited to just taking close-ups? Has anyone used this lens for something other than macro shots?

[Malaxos1]

This lens is for both. Macro lens means that it can focus a few inches from the subject as well as far away. They usually cost more than non macro lenses...Dean

[Scottes]

Any macro lens will do long distance, it's just that it *can* do very close distance. The optics of any real macro lens will be superb.

I have a Sigma 105mm Macro and I use it for anything whenever 105mm is right. My Sigma is slower to AF, but the optics are superb and it's a very good lens. If I had known better I would have gotten the Canon in a heartbeat.

[phizz6]

Thanks Scottes

I was hoping it could be used as a regular lens as well as for macro focusing. I am contemplating purchasing a 20D and really can't afford L lenses to begin. I have read good things about the sharpness and capability of this lens and being an f/2.8, I thought it would be a good dual purpose lens that would retain its value. I understand it will be a 160 mm because of sensor size on the 20D.

[Scottes]

Your reasoning is sound. If you can deal with a possibly slow AF then you'll be very happy with this lens. For the price the optics kick some butt. Yes, it will be 160mm on the 20D, and also 1.6:1 for macro.

[J Rabin]

Phizz6:
This is among my favorite Canon lens. In addition to macro use at work, I use it as a superb medium tele portrait lens. The resolution of detail blows the doors off my consumer lenses, even 12-15' feet from subject.
People sometimes remark about slower focus. Bah. Few weeks ago I was at Trexlertown PA velodrome track races. 10 pm at night under lights. This 100mm macro 2.8 is my only 2.8 fast telephoto. The pictures (contrast, color, resolution) even under ISO 1600 & flash are amazing consisdering conditions. Trouble was, even at 1/400 you can't stop motion blur of PA's own Marty Nothstein (Silver Atlanta, Gold Sydney, slow in Athens) sprinting at 43+ mph.
This is an L lens in disguise. I like its reach much better than a 50mm. Hope that opinion helps.
Jack

[J Rabin]

Phizz6:
Caution to my enthusiastic remarks: This is a long front heavy designed lens on a 700 gm camera like a 20D. A little unbalanced for walking around unless you're buying the battery grip. Much more stable on a tri or mono pod.
If you need a medium reach all-round lens that is also sharp, spring a $100 bucks extra for the 70-200mm f/4 L. Similar size and weight, exceptional quality, but far more flexible. You can't underestimate joy of a zoom letting your lens do your cropping! That's only weakness of the 100 macro for general use. You will not be disappointed in either. You will never sell either lens 10 years from now.
Originally, I bought the Sigma macro, took it home, saw how slow it focused and fact that barrel extends during focusing made it diffcult on skittish insects. Traded it 24 hrs later and happier for Canon.

[Adam Hicks]

I have the lens and love it... bought it for Macro toying around. Now that I have the 100-400L, it's rarely on the camera as it does like to hunt a lot. The optics are superior to the 100-400L in sharpness (it's a prime after all) but I'm constantly amazed at how sharp of a lens it is.

Have you also considered the 85mm 1.8? Faster lens and maybe a bit more usable focal length depending on what you're doing.

I don't know what you use for a walk around lens, but you might consider the Tamron 28-75 2.8 constant aperture Macro lens. It's cheaper (around $380 or so I believe) and I've used mine for every purpose you can imagine. Quite a bit faster focusing than the 100mm and it really never hunts. it's sharp and it's well built and the price is hard to beat!

Adam

[EXA1a]

.... Yes, it will be 160mm on the 20D, and also 1.6:1 for macro.
Nope. It will have still a 1:1 magnification ratio. Means: an object of the size of the sensor (~22mm) will be captured frame-filling on the sensor.

--Jens--

[EXA1a]

I don't know what you use for a walk around lens, but you might consider the Tamron 28-75 2.8 constant aperture Macro lens.
It's not a macro lens. It has a 1:3.9 magnification ratio.

--Jens--

[Scottes]

.... Yes, it will be 160mm on the 20D, and also 1.6:1 for macro.
Nope. It will have still a 1:1 magnification ratio. Means: an object of the size of the sensor (~22mm) will be captured frame-filling on the sensor.

In 35mm terms, which we were talking about, it will be 1.6:1.

[EXA1a]

.... Yes, it will be 160mm on the 20D, and also 1.6:1 for macro.
Nope. It will have still a 1:1 magnification ratio. Means: an object of the size of the sensor (~22mm) will be captured frame-filling on the sensor.

In 35mm terms, which we were talking about, it will be 1.6:1.
Does not matter in which terms you are thinking:
Any 1:1 macro lens will be
1:1 for 35mm Film, e.g. a 36mm object will be frame-filling on the 36mm wide film
1:1 for 1.6x sensors, e.g. a 22mm object will be frame-filling on the 22mm wide sensor.

Even on medium format film or on a 5mm sensor, this lens will be 1:1 at the close end!

--Jens--

[phizz6]

I would like to thank everyone for the input on the macro lens. The Canon 100 mm f/2.8 USM Macro will definitely be one of the lenses for my first DSLR. My thoughts were to begin with three lenses: the 100 mm f/2.8 USM Macro, either the 50 mm f/1.4 USM or the 50 mm f/1.8, and as a walk around the 24-85 mm f/3.5-4.5 USM. I am not quite sure if I should go for the kit (18-55 mm) when I am ready to buy (after all the dust settles over the 20 D lock-ups), or apply the $100 toward one of the other three lenses. Thanks again for all the good information.

Jim

[Scottes]

1:1 for 35mm Film, e.g. a 36mm object will be frame-filling on the 36mm wide film
1:1 for 1.6x sensors, e.g. a 22mm object will be frame-filling on the 22mm wide sensor.

So with a 1.6 crop digital camera I can take a full-frame picture of something that's smaller than 36mm, which means that in 35mm equivalencies it will be 1.6:1.

It is still 1:1 in digital sensor terms, but we weren't talking about that.

[EXA1a]

1:1 for 35mm Film, e.g. a 36mm object will be frame-filling on the 36mm wide film
1:1 for 1.6x sensors, e.g. a 22mm object will be frame-filling on the 22mm wide sensor.

So with a 1.6 crop digital camera I can take a full-frame picture of something that's smaller than 36mm, which means that in 35mm equivalencies it will be 1.6:1.

It is still 1:1 in digital sensor terms, but we weren't talking about that.
Scottes, you mix up physical properties of an optical device (=lens) and its behaviour on a certain camera.
To physically characterize a lens, the focal length is a good measure. Focal length does not change under any circumstances, it is independent of the camera. You will experience different angles of view with different camera bodies, that has been discussed to death and the verdict on it is: The focal length of a lens doesn't change but it "behaves" as if the focal length changes when you change the camera body with a different light-sensitive area (but only angle of view-wise!).
For Magnification ratio the same is true. The lens produces a 1:1 image, no matter what kind of film/screen/sensor you put behind. Of course, you need to know the size of the sensor in your camera to estimate the frame-filling object size, which is 1.6x smaller on a 1.6x sensor than on a FF sensor or film.
So, to avoid any confusion for the forum members, especially for the newbies, we shpould be quite strict on the terminology and on distinguishing between pure physical properties of a lens and the interaction of such a lens with a certain camera body.

I hope that clarifies.

--Jens--

[Scottes]

Regardless of however you wish to quantify it, the resulting image will seem like 1.6:1 when compared to 35mm. You can be concerned with physics. I'll be concerned with the final image.

[EXA1a]

Regardless of however you wish to quantify it, the resulting image will seem like 1.6:1 when compared to 35mm. You can be concerned with physics. I'll be concerned with the final image.
You just don't get it. I give up.

[Scottes]

Yeah, I do get it. But when someone asks if a 100mm macro will focus on something far away, then I don't think that they need to understand all the implications of the crop factor, resulting DoF, Circle of Confusion, etc, etc, etc.

Explain away all you want. I choose to keep it simple.

[EXA1a]

Yeah, I do get it. But when someone asks if a 100mm macro will focus on something far away, then I don't think that they need to understand all the implications of the crop factor, resulting DoF, Circle of Confusion, etc, etc, etc.

Explain away all you want. I choose to keep it simple.
There is a big difference between "plain wrong" and "simple". I can't agree to simplifications which ignore the facts. Maybe it's just my natural scientific way of logical thinking.

[Scottes]

You're not wrong in that way of thinking. But when you've been down that long dark corridor many times you begin to realize that you don't need an engineering degree to take a picture. Regardless of how many times you compute the DoF of a 1.6 crop factor sensor with a 100mm macro lens and 37mm of extension tubes and then factor in a CoC of 0.019, well, you're going to take a few shots before you're happy with the DoF.

I was in your shoes a year ago. I am also an engineer and a math nut. I know longer compute the DoF on the fly - I just turn the wheel to change the aperture. I don't compute the Angle of View, I just look through the viewfinder.

The end result is the picture.

[Jon]

The lens says "life size" or "1x". That is not going to change regardless of the sensor size. The image on the sensor will be 1x with the subject at closest focus. That's what Canon says it does, and that's a constant. Now how much you enlarge it for reproduction is a totally different issue, unrelated to the lens' reproduction ratio. And thinking in terms of the finished picture, blowing a "life-size" 35 mm. image up to 7x10, you''ve taken the picture at 10:1. Do you believe that?

[CyberDyneSystems]

I can not tell you how many threads there are buried in "EOS" that hash out the differing arguments on the "X-Factor" created by sensor size as compared to 35mm.

I'll admit the introduction of the "macro" aspect adds a new twist.. but all in all it is still the same "1.6X" debate.


In the end.. little is gained from any of the discussion, especially when one feels convinced that there viewpoint is the only correct one.

So.. who here is smart enough to walk away from the futility?

[KennyU]

Some long tele images with my 100 f/2.8 Canon macro. These are unaltered right out of the camera

http://kennyunger.smugmug.com/gallery/213131[/url]

[phizz6]

KennyU

Thanks for posting the 100 mm Macro Pics. They look very sharp--just what I wanted to see.

[kraterz]

For Scottes : what you're saying is plain wrong, it is not a simplification.

Let's start with the 100/2.8 on 35mm film. It can capture an area of 24x36mm and record this on a film in a 24x36mm frame. That makes the reproduction ratio 1:1.

Fast forward to a DSLR. The 20D's sensor is 22.5 x 15.0 mm in size. When you have the 100/2.8 at its closest focusing distance, the 20D only sees the centre portion of the frame, i.e., 22.5 x 15.0 mm. In real life, if you have a ruler and focus the 100/2.8 down at 1:1, you can only see 22.5mm on the long end, not 36mm, because of the 1.6 crop. This 22.5 x 15.0 mm area is recorded on the 22.5 x 15.0 mm sensor of the 20D.

Hence, it is still a 1:1 reproduction, whether you use it on a 35mm film camera or a 20D.

You can say you have a 1.6:1 magnification only if you can record a 22.5 x 15.0 mm area on to a 35mm frame (24 x 36 mm). You can only achieve this with extension tubes. The lens cannot do this by itself. It is simple maths.